import java.util.Scanner;

public class Test1 {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        // 注意 hasNext 和 hasNextLine 的区别
        while (in.hasNextInt()) { // 注意 while 处理多个 case
            int n = in.nextInt();
            int[] prices = new int[n];
            for (int i = 0; i < n; i++) {
                prices[i] = in.nextInt();
            }
            int min = 0x3f3f3f3f;
            int max = -0x3f3f3f3f;
            int maxvalue = 0;
            for (int price : prices) {
                if (price < min) {
                    min = price;
                    max = price;
                }
                if (price > max) {
                    max = price;
                    maxvalue = Math.max(maxvalue, max-min);
                }
            }
            System.out.println(maxvalue);
        }
    }
}
